Conveyer control



W. H. BERNADT CONVEYER CONTROL May 5, 1931.

Filed Dec. 27, 1929 Z0617 fer 7i: Bernadi Famed May 5, 1931 UNITED...stares. OFFICE WALTER n. tsi srgatqgm ou Appllcationl ill ed w 27;192's." seriariwo. 418,806.

grading apparatus upon a succession of belt conveyers and in someinstances it is discharged from one conveyer directly onto another. Itsometimes happens that the path of travel of the coke from its startingpoint to the point where it is discharged for final disposal is brokenas a result of the stopping or slowing up in speed of one of theconveyers or the choking of the crushers or 2 grizzlies. When thisoccurs, unless the conveyers which are delivering the coke to thedisabled mechanism are stopped, an accumulation of the coke developswhich increases to a point where its overflow occurs. This 7 requires aninterruption in the operation of the entire line of conveyers, crushersand graders until the material has been cleared away by hand shoveling,the time required to do this depending upon the elapsed time be- $9tween the breakdown of the conveyer or other mechanism andthe stoppingof the line of feed conveyers. 4

The principal object of the present invention is to provide a device tobe used in conjunction with conveyers, crushers, grizzlies and othermechanisms which will become efl'ective immediately, upon theaccumulation of material in the path of travel beyond a predeterminedheight, to sto the conveyer or conveyers which are feed ng the materialto that point where the excessive accumulation has commenced.

The device is designed to stop the feed conveyers before theaccumulation referred to has reached a point where overflow occurs andas a result therefore, no hand shoveling, with the resultant loss oftime, is necessary and immediately upon the repair of the defectivemechanism the entire line of mechanisms may be started at once.

one application of my invention.

s The invention is illustrated in the accompanym'g drawings in whichFigure ,I-i's. a vertical section of a grizzly and feeding mechanismtherefor showing Figure12is an end elevation of the same. Figure3Ishowsthe control mechanism in conjunction with a. ho per which is arranged tofacilitate the transt dr of the material from one conveyer to another.While the invention is described in connection with treating andconveying of coke it is to be understood that such description is merelyfor purposes of illustration and that in fact the invention is availablefor other mechanisms and purposes so long as the electrical conductivityofthe material being acted upon is suitable for the purposes in view.

The control mechanism is illustrated in Figures 1 and 2 in connectionwith a grizzly 4 and a feed conveyer 5 therefor, only the essentialparts of the apparatus being shown for purposes of clarity. The feedconveyer 5 may be driven by an electric motor 5a. The grizzly 4 includesspaced bars 6 which provide screening openings 7. The coke orothermaterial is discharged from the feed conveyer 5 onto the grizzly 4- downwhich it rolls to a chute 8 from whence it may be carried away in anysuitable manner. In the passage of the material from the feed conveyerto the discharge chute 8, however, the smaller particles are separatedtherefrom by the grizzly 4, the finer particles of the material 35passing through the openings 7 and dropping upon a conveyer 9 which ispositioned beneath the grizzly and which is adapted to convey them to adilferent point of discharge. The construction described to this pointis 90 representative of apparatus for grading coke and is standardequipment.

In the grading of the coke it may ha' pen 1 that the screening openingsin the grid become choked or one of the conveyers 8 and 9 breaks down orslows up appreciably. Upon such an occurrence if the conveyer 5continues to deliver its usual flow of material, the materialaccumulates and rapidly reaches a point where it overflows its path.

This requires its subsequent handling by hand and also chokes up partsof the apparatus. The amount of material accumulating in the path offlow and overflowing the same depends, of course, upon the time that thefeeding conveyers continue in operation after a mechanism in the path offlow has become disabled.

In order to avoid such occurrences, I propose to employ a switchmechanism which is controlled by contact members positioned a-djacentthe path of flow of the material being acted upon and in such relationtherewith that if for any reason the material accunuilates in the pathbeyond a certain height a circuit is closed to operate the switchmechanism and break the circuit through the motor which is driving theconveyer or other mechanism feeding that portion of the apparatus wherethe accumulation has commenced.

The switch and automatic operating mechanism therefor which areindicated as a whole at C (Fig. 1) may be positioned wherever desiredbut are preferably located in the switch box containing the switchesemployed in connection with the other motors of the apparatus.

Means for starting the automatic switch operation mechanism is, asstated, positioned adjacent the path of flow of the material being actedupon at any number of points desired. As illustrated in Figuresl and 2each of said means comprises pairs of depending contact arms 10 whichare pivotally supported at their upper ends between brackets 11 securedto cross members 12. The cross members 12 may be supported by the sidewalls of the grizzly at such a distance from the bottom thereof that thecontact arms are held-above the screening surface of the grizzly at sucha height that in the normal operation of the apparatus the materialpasses beneath the said arms without touching them. The cross members 12are, of course, insulated from the depending arms 10 and theirsupporting brackets. I

As illustrated in-Figure 1, the feed conveyer may be started by closinga circuit through the motor 5a. The circuit is closed by operating thehand switch 13 of the control 'mechanism C. A circuit is thereuponestablished through the A side of the power line, contacts 14 and 15,which are normally held closed by the spring 16a, switch 13, solenoid 16and out the B side of the power line. The solenoid 16, upon beingenergized closes the switch 17 and the motor circuit is closed. Theclosing of the switch 17 however, also closes a circuit by means ofwires 18 and 19 through the primary winding of a transformer 21. Thesecondary winding of the transformer forms part of a normally opencircuit which includes wire 21grounded to the frame of the grizzly as at22 and wire 23 which is connected to electric magnets 21. The circuitthrough wire 23 and magnets 24 continues through wires 25 to the bindingposts 26 which are electrically connected through the brackets 11 to thearms 10.

It will thus be obvious that during the normal operation of theapparatus the secondary circuit will be open and the spring 16a willhold the contacts 14 and 15 closed to maintain the encrgization of themotor 5a. However, should the coke or other conductive material which isbeing treated back up against any one of the fingers 10, a closedcircuit is established from that linger through the coke which hasbacked up beneath it, the frame of the grizzly, wire 21, magnets 24,wire 25 and the electric magnets 24 are therebyenergized to attract thearmature 27 which opens the contacts 1 1 and 15 to break the motorcircuit and stop the feed conveyer 5. Upon the clearing away of thematerial beneath the arms 10, the secondary circuit will be broken and acircuit will again be closed through the motor 511. It will thus beapparent that by utilizing the invention in the manner described a feedconveyer will be automatically stopped when the material beyond thedischarge end thereof has reached a predetermined level and that anyoverflow of the material may, therefore, be effectually prevented.

In Figure 3 the invention is illustrated in connection with twoconveyers with a hopper arranged between the two and adapted tofacilitate the transfer of the material from one of the conveyersto theother. The feed conveyer 28 which is driven by motor 29 delivers thematerial into the hopper 30. The discharge mouth 31 of the hopper isarranged to deliver the material received from the feed conveyer 28 to asecond conveyor 32 which is driven by the motor 33.

In connection with this modification of the invention it is to be notedthat in grading and crushing coke, it is the practice to utilize such anarrangement of conveyers to receive the liner particles of coke from thegrizzly and carry them to the ultimate point of discharge. In such anarrangement the hopper 30 would be positioned beneath the upper end ofthe conveyer 9 (illustrated in Iigure 1). In

other words the said conveyer 9 would be utilized to feed material tothe hopper 30 instead of the conveyer 28 shown in Figure 3. In any eventit is preferred that the motors for driving the various conveyers beadapted for independent starting, that is to say, have independentswitches which permit them to be started preferably in sequence from theend of the line toward the beginning of the line. In such a constructionthe automatic control mechanisms are preferably arranged so as not onlyto stop the conveyer feeding directly to the point where theaccumulation has commenced but also all of the conveyers in the linewhich precede it, the conveyers beyondthe point of accumulationcontinuing in operation-to clear that portion of the apparatus.

To this end, therefore, the motor 33 (Fi ure 3) is started first byclosing the switcv 36. After the switch 36 has been closed, the

utilized in the first embodiment illustrated,

. I propose to employ contact fingers 34 which are preferably suspendedby a support 35 from the inner wall of the hopper and over the dischargemouth of the same, the fingers 34 being insulated from the support 35 asat 35a. The secondary circuit of the transformer 20 includes wire 21which may be grounded to the hopper 30, magnets 24 for operating'thearmature 27 and wire 25 connected to the fingers 34. If for any reasonthe conveyer 32 should stop or, slacken its normal speed and the cokebackup in the hopper to such a height as to contact with the fingers 34the secondary circuit will be closed, utilizing the coke and hop 'er aspart of the circuit, to break the circuit throu h the motor 28 asdescribed in the first emb iment of the invention. While the circuitthrough motor 28 is broken the circuit through motor 33 will, of course,not be effected and the conveyer 32 willcontinue in operation. a

In both embodiments of the invention the relation between the primaryand secondary windings of the transformers is preferably such that thevoltage in the secondary circuits is not high enough to be dangerous toworkmen. However, the current, voltage and frequency may be varied inorder to meet different conditions such as, for exam le,materialsofiering different resistances to t e passage of current.

Having described my invention I claim 1. In a paratus for transferringelectrically con uctive material from one point to another, a conveyerfor delivering the material to a point of discharge, a motor operativelyconnected to said conveyer, a normally closed circuit through the motor,means arranged to provide a path of flow for the material dischargedfrom said conveyer, contact means arranged adjacent the said means andelectrically controlled means operable to break the circuit through saidmotor when the material in the path of flow has reached a heightsufiicient to contact with said contact means, the said materialproviding a conductor between said contact means and said electricallycontrolled means.

2. In apparatus for transferring elec-.

trically conductive material from one point to another, a conveyer fordelivering the material to a point of discharge, a motoroperatively'connected to said conveyer, a normally closed circuitthroughthe motor, means. arranged to provide a path of flow for the materialdischarged from said conveyer a contact member ivotall mounted adjacentsaid means an electrically controlled means operable to break thecircuit .through said motor when :the material in the path. of flow hasreached a height suflicient to contactwith said contact member, the

said material providing a conductor between said contact member and saidelectrically controlled means.

3. In apparatus for transferring material from one point to another, aconveyer for delivering the material to a point of dis-- charge, amotor'operatively connected to said conveyer, a' normally closed circuitthrough said motor, means arranged to provide a path of flow for thematerial discharged from said conveyer, automatic means for breaking thecircuit throu h said motor said means including a trans ormer having itsprlmary winding in the motor circuit, the

secondary winding of said transformer being included in a normally opensecondary circuit and means adjacent the path of flow and adapted whenthe material in the path of flow has reached a predetermined height toclose said secondary circuit.

4. In apparatus for transferring material from one point to another, aconveyer for delivering the material to apoint of .dis charge, a motoroperatively connected to said conveyer, a normally closed circuitthrough said motor,-means arranged to provide a path of flow for thematerial discharged from said conveyer, automatic means for breaking thecircuit through said motor comprising a transformer having its primarywinding in the motor circuit, the secondary windingof said transformerbe ing included in a normally open secondary circuit and means adjacentthe path of flow and adapted when the material in the path of flow hasreached a predetermined height to close the secondary circuit and effectthe operation of said automatic means, said ma-' terial constituting apart of the said secondary circuit.

5. In apparatus for transferring electrically conductive materials fromone point to another, a conveyer for delivering the materials to a pointof discharge, a motor operatively connected to said conveyer, a normallyclosed circuit through said motor and automatic means for breaking thecircuit through said motor comprising a transformer hating its primarywinding in the motor circuit, a normally open secondary circuitincluding the secondary winding of said transformer, an electric magnetin said secondary circuit, means in said circuit arranged adjacent thepath of flow of the materials and. ada ted when the materials thereinhave reached a predetermined height to cooperate 5 with said materialsto close said secondary circuit, thereby to operate said magnet andbreak said motor circuit.

6. In apparatus for transferring electrically conductive materials fromone point to another, a conveyer for delivering the materials to a pointof discharge, a motor operatively connected to said conveyer, a normallyclosed circuit through said motor, a second conveyer for carryin oil thematerials discharged from the rst mentioned conveyer, means arrangedbetween the two conveyers for facilitating the transfer of thematerials, contact means carried by said means, and electricallycontrolled means operable to break the motor circuit when the materialsbeing transferred back up beyond their normal height to contact withsaid contact means, the said materials providing a conductor betweensaid contact means and said electrically 25 controlled means.

' 7. In apparatus-for transferring electrically conductive materialsfrom one point to another, a conveyer for delivering the materials to apoint of discharge, a motor operatively connected to said conveyer, anormally closed circuit through said motor, a second conveyer forcarrying oil. the materials discharged from said first mentionedconveyer, intermediate means arranged between the two conveyers forfacilitating the transfer of the materials from one to the other,automatic means for breaking the circuit through said motor comprisingan armature carrying a contact, a magnet for operating said armature,said magnet being included in a normally open circuit and contact meansas a part of said circuit carried by said intermediate means and adaptedto contact with the materials being conveyed should the materials backup in the intermediate means beyond a predetermined height, saidmaterials being utilized in such case as a conductor to closethe'normally open circuit through said magnet.

50 In testimony whereof I ailix my signature.

WALTER H. BERNADT.

